Pump or a motor employing a couple of rotors in the shape of cylinders with an approximately cyclic section

ABSTRACT

A pump or motor having two rotors of a defined shape such as to ensure contact between the two rotors in all positions.

United States afiem 1191 Daido Apr. 10, 1973 [54] PUMP OR A MOTOR EMPLOYING A [56] References Cited COUPLE 0F ROTORS IN THE SHAPE UNTTED STATES PATENTS 0F CYLINDERS WITH AN APPROXIMATELY CYCLIC SECTION 20,796 7/ 1858 Holly ..418/204 1,771,863 7/1930 Schmidt ..'.....4l8/204 Inventor: Takayoshi Daido, 624 PP J 1,837,714 12 1931 Jaworowski ..418/204 Himeji, Japan 3,078,807 2 1963 Thompson ..418/204 Filed: P 1971 FOREIGN PATENTS OR APPLICATIONS [21] Appl. No.: 132,776 696,469 9/1940 Germany ..418/204 624,371 9 1961 Italy ..418 204 30 F A H ti Pri D ta orelgn pp ca on onty a Primary ExaminerAllan D. Herrmann Apr. 17, Japan Attorney sparrow & Sparrow [52] US. Cl ..418/150, 418/204 57 ABSTRACT [51] Int. Cl ..F0lc 1/24, F03C 3/00, F040 1/14 [58] Field 61 Search ..418/204, 150 A P of havmg two rotors of a defined Shape such as to ensure contact between the two rotors in all positions.

1 Claim, 6 Drawing Figures PUMP OR A MOTOR EMPLOYING A COUPLE OF ROTORS IN THE SHAPE OF CYLINDERS WITH AN APPROXIMATELY CYCLIC SECTION This invention relates to a pump or a motor with two cylindrical rotors having an approximately cyclic section fitted in a casing formed by the inner circumferences, excepting the crossing part, of two parallel cylinders with equal diameters made partially to intersect each others.

In the accompanying drawings,

FIGS. 1 to 4 are illustrations of this invention,

FIGS. 5 and 6 are to show the modification of the rotors.

Numeral 1 denotes the section of the inner circumference of the casing, the distance between the centers and 0 being 0,0 2 (R-e), consisting of two circular arcs of two circles 1a and lb with equal radius R excepting those included between A and B which are crossing points. Numerals 2 and 3 are two rotors each with eccentricity or e of eccentric radius e as its center and with cylindrical circumference of radius r R e. In FIG. 1, the eccentricities e and e are on the straight line 0 -0 and its extension, the rotor 2 touches the circle 1b with the center 0 at the point C and the rotor 3 touches the circle 1a with the center 0- at the middle point D of the imaginary circular are between A and B corresponding with the cut-off portion. With the chosen size of the internal diameter of the casing and of the external diameter of the rotor, the rotors 2 and 3 naturally touches each other externally at D. Numerals 4 and 5 denote an inlet or an outlet port of working fluid and their crossing points as shown in the figure of the inner circumferences 1a and 1b of the casing are denoted by G, H, K and L.

In the above case, it is supposed that the eccentric radius e and the eccentricity e/R being chosen sufficiently small, the circular are between G and H, which are the crossing points of the inlet or the outlet port of the working fluid shown in FIG. 1 and the inner circumference 1a of the casing, within the limits of the angle 0 involved at the center 0 is considered approximately equal to the circular arc of the rotor with the center e within this angle 0 and that the angle 0 is a small one at least less that 90. If the rotors 2 and 3 respectively with O and O, as their center are made to revolve at a uniform speed in the directions of the arrows in opposi-' tions to each other, when they revolve 90 from the above and reach the positions shown in FIG. 3, there arises a small gap between the circumferences of the rotors 2 and 3, but they go on revolving nearly keeping the state of contact with each other, and if a little modification and processing are done upon the circumferences of the rotors 2 and 3 for the purpose of stopping the gap, the working of the pump letting out the working fluid from the inlet or the outlet port 5 or contrariwise, the working of the motor by the forced working fluid can be performed.

FIGS. 2 to 4 are ones in which the states of contact of the rotors 2 and 3 in their revolving positions are examined in drawings: FIG. 2 showing when the rotors 2 and 3 are turned half of the angle degrees 0 as far as radius O,D and 0,6 come together, FIG. 3 when the rotors 2 and 3 turn 90 from the positions shown in FIG. 1, and FIG. 4 when the rotors 2 and 3 turn as far as the radius 0 C and 0 K come together. Theoretically,

excepting when the rotors 2 and 3 are in the positions shown in FIG. 1 and in the positions when they turn 180 from the above, there is no point of contact between them, but if a little processing is done on the circumferences of the rotors 2 and 3 so as to make them touch each other at each revolving position, leakage is practically as nothing and the working of the pump or of the motor can be performed without hindrance.

FIGS. 5 and 6 are to illustrate how to modify the circumferences of the rotors 2 and 3 in other to keep them constantly in tough with each other.

Assume that the rotor circles 2 and 3 shown in full line, with the centers 0 and O in the casings respectively as their centers of rotation, rotate at a uniform speed in the opposite directions from each other as shown by the arrows, and the points of contact C and D of the circles 2 and 3 on the casing circles lb and 1a, each turning the angle 0, become C, and D and while e and e which are respectively the cent of the circle 2 and 3, are transferred to e, and e these circles 2 and 3 are transferred to circles 2' and 3' shown in dotted line. At this case, chords C C and D D of the circles 2 and 3 shown in full lines at the symmetrical positions with the lines C -C and 0 D to the straight line passing through the center 0 1 and 0 turns to fall on the straight line passing through the center 0 and O and the new positions are respectively shown with dotted lines C -C and D D,,. There is a small gap between C and D (1 when this gap is assumed to be 28, the length 8 is added to each end of the chords C -C and D D, thus forming N,N and N -N as shown in the figure. When N, and N assumed to be the modified points of the rotor 2 and N and N to be those of the rotor 3, both rotors 2 and 3 constantly externally touch each other at the point N. However,

and as it is obviously understood with each from the illustration that N N NN, 2M,N 2M N if it is assumed,

N M M N NM NzNz r,

the rotors 2 and 3 can be made to rotate with the centers 0 and 0 of the casings as their centers of rota- Il-O1Il all running through the point 0, to take up the points on either side a length r distant from M's which are points of intersection where these straight lines cross the circumference of the circle m. (In this figure, M is identical with 0 in the case of I-O -I and in case of IV-O IV running on the line e and 0 e is identical with M).

And in FIG.6, in case the point O is the origin of coordinates, the x axis of co-ordinates is plus on the right side of the straight light 0,-IV from the origin and the I Y axis of co-ordinates is plus on the upper side of the straight line 0 -1 from the origin and O'e' =e, the point of the modified circle is represented by One of the characteristics of the present invention is that to iessen the pulsating flow of the working fluid, more than one sets of rotor and casing having the same rotor shaft in common but 90 different in position from each other are arranged, in which the inlet or the outlet ports 4 and 5 are joined in series so as to drive the rotors with a single motive power or contrariwise, to drive a single load by means of more than one sets of rotors. Another merit of this invention is that compared with the pumps of other types eg the plunger pumps or the screw pumps, this invention is remarkably simple in structure and can be provided cheaply. It is another merit of this invention that regardless of the number of rotation, the pump or the motor can produce high pressure, making no noises.

What I claim:

1. In a pump or motor having (a) a pair of chambers the inner surface of which corresponds to the nonover-' lapping surfaces of two parallel and equal intersecting cylinders, (b) an inlet port and an outlet port on the two lines of intersection of said chambers, and (c) a rotor mounted in each chamber for eccentric rotation therein about the longitudinal centerline of said chamber, the improvement comprising a rotor of modified circular cross-section and otherwise cylindrical shape, the outer surface of said rotor in cross-section being defined by the loci of points having coordinates on an x-axis equal to cos 8 (r i arms 0) and on the y-axis equal to sin 0 (r i e'cos 0) where:

r is equal to Re;

R is the radius of the cylindrical chamber;

e is the distance from the center of the rotor to the center of the rotors eccentric rotation;

0 is the angle measured at the center of eccentric rotation of any given point on the surface of the rotor above the line intersecting the center of the rotor and the center of eccentric rotation;

said x-axis corresponding to a line perpendicularly intersecting the two longitudinal centerlines of the cylindrical chambenand said y-axis corresponding to a line perpendicularly intersecting both said x-axis and the centerline of said cylindrical chamber in which the rotor is disposed. 

1. In a pump or motor having (a) a pair of chambers the inner surface of which corresponds to the nonoverlapping surfaces of two parallel and equal intersecting cylinders, (b) an inlet port and an outlet port on the two lines of intersection of said chambers, and (c) a rotor mounted in each chamber for eccentric rotation therein about the longitudinal centerline of said chamber, the improvement comprising a rotor of modified circular cross-section and otherwise cylindrical shape, the outer surface of said rotor in crosssection being defined by the loci of points having coordinates on an x-axis equal to cos theta (r + OR - e.cos theta ) and on the y-axis equal to sin theta (r + OR - e.cos theta ) where: r is equal to R-e; R is the radius of the cylindrical chamber; e is the distance from the center of the rotor to the center of the rotor''s eccentric rotation; theta is the angle measured at the center of eccentric rotation of any given point on the surface of the rotor above the line intersecting the center of the rotor and the center of eccentric rotation; said x-axis corresponding to a line perpendicularly intersecting the two longitudinal centerlines of the cylindrical chamber; and said y-axis corresponding to a line perpendicularly intersecting both said x-axis and the centerline of said cylindrical chamber in which the rotor is disposed. 